Hot press molding, which is increasingly employed as, for example, a method for molding a steel sheet such as the material of an automobile component using a high-tensile steel sheet, can mold a steel sheet in a stage of low deformation resistance by molding it at high temperature, and furthermore can provide a component etc. with high strength and high shape accuracy by press molding without causing molding defects such as deformation after molding, by hardening by quenching based on rapid cooling using the jetting of cooling water.
In such a hot press molding method, press molding is performed such that a steel sheet is heated at a prescribed temperature, for example 700° C. to 1000° C., in a heating furnace before press molding and then the steel sheet is conveyed to a hot press molding apparatus.
As the technology of heating thus using a heating furnace, conventionally, a mechanism in which a steel sheet is heated by heaters provided in, for example, an upper portion and a lower portion of the interior of a furnace while the steel sheet is horizontally supported by rollers and conveyed by the rollers in the furnace has commonly been used (Patent Literature 1).